Treesearch

Conserving multiple facets of biodiversity is important for sustaining ecosystems. However, understanding relationships between faunal diversity and measurable ecosystem quantities, such as heterogeneity and productivity, across continental scales can be complicated by disparate methods. We developed standardized approaches using lidar data and spectral greenness data (via NDVI; Normalized Difference Vegetation Index) from 637 sampling plots across four sites in North America, Europe, and Asia to test the local effects of habitat heterogeneity and productivity on taxonomic, functional, and...

Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive beetle from Asia, spreads through human-mediated movement and active flight. The effects of adult feeding and overwintering conditions on A. planipennis energy reserves (e.g., lipid, glycogen, and sugars) and flight are poorly understood. We conjectured that the potential energetic demands associated with the production of cryoprotectants might affect dispersal capacity and partially explain slower spread of A. planipennis in Minnesota than in the other states. Two studies sought to measure the effects...

The emerald ash borer, Agrilus planipennis Fairmaire, is invading North America and Europe but has not yet reached its ultimate distribution. Geographic differences in host availability and winter temperatures might affect where this species will occur. In central North America, black ash (Fraxinus nigra) is more abundant than green ash (F. pennsylvanica) at northern latitudes, but much of our current understanding of A. planipennis cold tolerance is based on observations of overwintering larvae from green ash. The effects of black and green ash on the cold hardiness of A. planipennis...

The walnut twig beetle (Pityophthorus juglandis Blackman) (Coleoptera: Curculionidae) is a regulated pest in the United States due to its causal role in thousand cankers disease of walnut trees, including the commercially valuable eastern black walnut (Juglans nigra L.). Several state quarantines designed to limit spread of P. juglandis regulate movement of kiln-dried walnut lumber that contains bark. Previous research demonstrated that P. juglandis will enter and re-emerge from bark of kiln-dried, J. nigra slabs subjected to extreme beetle pressure (baited with a pheromone lure and hung...

The South’s production of pulpwood decreased from 61.8 million cords in 2014 to 60.6 million cords in 2015. Roundwood production decreased by 260 thousand cords to 49.5 million cords and accounted for 82 percent of the South’s total pulpwood production. The use of wood residue dropped 8 percent to 11.2 million cords in 2015. Georgia and Alabama led the South in total production, with 10.1 and 9.6 million cords, respectively. In 2015, 79 mills were operating and drawing wood from the 13 Southern States.

The statistical properties of candidate methods to adjust for the bias in growth estimates obtained from observations on increasing interval lengths are compared and contrasted against a standard set of estimands. This standard set of estimands is offered here as a solution to a varying set of user expectations that can arise from the jargon surrounding a particular data aggregation procedure developed within the USDA’s Forest Inventory and Analysis Program, specifically the term “average annual” growth. The definition of a standard set of estimands also allows estimators to be defined and...

Large tropical trees store significant amounts of carbon in woody components and their distribution plays an important role in forest carbon stocks and dynamics. Here, we explore the properties of a new lidar-derived index, the large tree canopy area (LCA) defined as the area occupied by canopy above a reference height. We hypothesize that this simple measure of forest structure representing the crown area of large canopy trees could consistently explain the landscape variations in forest volume and aboveground biomass (AGB) across a range of climate and edaphic conditions. To test this...

Nontimber forest products (NTFPs) are fundamental to the functioning of healthy forests and play vital roles in the cultures and economies of the people of the United States. However, these plants and fungi used for food, medicine, and other purposes have not been fully incorporated into management, policy, and resource valuation. This report is a forest-sectorwide assessment of the state of the knowledge regarding NTFPs science and management information for U.S. forests and rangelands (and hereafter referred to as the NTFP assessment). The NTFP assessment serves as a baseline science...

Hurricanes are an important disturbance in the tropics that can alter forest ecosystem properties and processes. To understand the immediate influence of hurricane disturbance on carbon cycling, we examined soil labile organic carbon (LOC) in a Canopy Trimming Experiment (CTE) located in the Luquillo Experimental Forest of Puerto Rico. We trimmed tree canopy and deposited debris (CTDD) on the forest ground of the treatment plots in December 2014, and collected floor mass samples and 0–10 cm soil samples three weeks before the treatment, as well as at scheduled intervals for 120 weeks after...

Emerald ash borer (EAB; Agrilus planipennis Fairmaire) is the most devastating insect pest of North American ash species, including black ash (Fraxinus nigra Marsh.). As a first step in an effort to develop transgenic black ash plants resistant to EAB, we successfully established an efficient Agrobacterium-mediated transformation system for black ash hypocotyls. Kanamycin and timentin at 40 and 300 mg L−1, respectively, were most effective to select transformed explants and control excess Agrobacterium growth. Using a plant transformation vector harboring the enhanced green fluorescent...